Charl Schwartzel hits a bunker shot on the 15th hole during Saturday's third round of the U.S. Open at Merion Golf Club. / Matthew O'Haren, USA TODAY Sports

by Christine Brennan, USA TODAY Sports

by Christine Brennan, USA TODAY Sports

ARDMORE, Pa. â?? There's still one more round to be played at the 2013 U.S. Open, but we already know who won: Merion Golf Club. A golf course built in 1912 -- the year Fenway Park opened and the Titanic sank, when woods actually were made of wood and golf balls could not fly 300 yards -- has not only held up against an onslaught from the future, it has triumphed and been reborn.

So-called golf experts thought the pros of today would eat this place alive after a good soaking from the storms earlier in the week.

What in the world were they thinking?

After Saturday's third round, only one player is in red numbers. Everyone else is even par or over par â?? way over par in some cases. After an even-par 70 on Saturday, Phil Mickelson goes into the final round on Father's Day, on his 43rd birthday, at 1-under for the tournament, one stroke ahead of Hunter Mahan, Charl Schwartzel and Steve Stricker.

"This," Mickelson said after his round, "is a really fun challenge. This is a really hard challenge."

How could so many people have been so wrong about such a well-known place? It appears they mistook a shorter than usual golf course for being an easier than usual golf course, somehow forgetting about the tall rough, the stunningly difficult greens, the blind shots and the strategic precision Merion demands every minute a golfer is playing the course.

"It was cracking all the guys up at the beginning of the week," said England's Paul Casey, who shot a 1-over 71 on Saturday for a 6-over total, good for a tie for 16th. "Guys like Frank Nobilo (of the Golf Channel) saying it's going to be 62s or 63s around here. And we didn't know which golf course he was talking about, because we knew this was going to be a brutal test.

"I love the fact that this is a short golf course," he continued, "and it's making my hair go gray, that's all I know. Golf courses don't have to be long to be difficult. This is a wonderful example of that. Maybe the best hole out there would be something like 13, the shortest hole on the golf course. It's wonderful. I'd love that we could come back to more and more short golf courses just as this."

The way this week has gone, the U.S. Golf Association might decide to do just that. It would appear to be the perfect U.S. Open venue, oozing history, but just modern enough to create those intriguing moments TV viewers adore, like when Nicolas Colsaerts spent a few minutes playing a couple of shots out of an evergreen around the 18th green Saturday.

"If you're just not a hundred percent on top of your game, it's going to expose some of your flaws or weaknesses," said Rory McIlroy, who has been subject to that exposure, shooting 5-over in the third round for an 8-over-par total score.

Not everyone watching is loving the experience, however. This might be the toughest U.S. Open course in memory to get around on foot. Spectators certainly have not been happy to trek over hill and dale to suddenly find themselves at a dead end, unable to get close to a green or tee box. Then again, the charms of Merion usually outweigh the frustrations â?? at least for those not playing in the tournament.

The final five holes are the quirkiest and most intriguing finishing holes imaginable, tight and foreboding, dripping in history and criss-crossing each other so everyone will know everyone else's business come Sunday afternoon.

"It's the teeth of the course," said Mahan, who will play with his good friend Mickelson on Sunday. "You just don't know what's going to happen. It's going to be a very, very exciting finish because I don't think any lead is safe, and there's an opportunity to make two or three birdies in there. So it's a great finish ... and 18 is 530 yards uphill, so it's a brutal hole."

No. 18 also is one of the most historic holes in the game, for it is where Ben Hogan hit his famous 1-iron to force the playoff in which he won the 1950 U.S. Open.

Early in the week, there was all kinds of chatter about players hitting 4- or 5-irons, or hybrid clubs, from that spot, as if Merion wouldn't be able to hold up to the players' 21st century, technologically-enhanced power.

Wrong once again. Three of the top four on the leaderboard bogeyed 18 on Saturday.

But even before the reality of Merion hit them, there was reverence. When Masters champion Adam Scott came to the course to practice a few weeks ago, he stopped in the pro shop to make a purchase. He wanted to buy a poster to frame for his office. It was the black-and-white photo of Hogan and his 1-iron.